Toothbrush

ABSTRACT

A toothbrush having a top side, an opposite bottom side, a head on which tooth cleaning elements are provided, a handle having walls and a recess, and a neck which connects the head to the handle. The recess is located on the side of the handle opposite the side having the tooth-cleaning elements and is open only toward the bottom side so that the handle walls bordering the recess form an inverted u-shaped cross-section.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of prior copending International Application No. PCT/IB2009/054791, filed Oct. 28, 2009, designating the United States.

FIELD OF THE INVENTION

The present invention relates to a toothbrush.

BACKGROUND OF THE INVENTION

Toothbrushes are well known and are often made from plastic. However, it would be advantageous to provide a toothbrush, which can be manufactured at a low cost using less plastic material. It would also be advantageous to provide a toothbrush that can be used conveniently and ergonomically by humans for the various types of toothbrush handling which vary greatly in different cultures around the globe.

SUMMARY OF THE INVENTION

A toothbrush that has a top side, an opposite bottom side, a head on which tooth cleaning elements are provided, a handle having walls and a recess and a neck which connects the head to the handle. The recess is located on the side of the handle opposite the side having the tooth-cleaning elements. The recess is open only toward the bottom side so that the handle walls bordering the recess form an inverted u-shaped cross-section.

These and other features are described in more detail in the following description and the respective drawings, where the features, either alone or in any combination, may constitute the subject matter of the invention independently of how they are combined with one another in the claims.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective diagram of the top side of a toothbrush according to the invention,

FIG. 2 shows a top view of the top side of the toothbrush according to FIG. 1,

FIG. 3 shows a side diagram of the toothbrush according to FIG. 1,

FIG. 4 shows a longitudinal sectional diagram through the toothbrush according to FIG. 1 along the line of intersection A-A in FIG. 2,

FIG. 5 shows a top view of the bottom side of the toothbrush according to FIG. 1, and

FIG. 6 shows a perspective diagram of the bottom side of the toothbrush according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a perspective diagram of the top side of a toothbrush having a head 1, a neck 2 connected thereto and a handle 3 which is in turn connected to the neck. The top side of the toothbrush has tooth-cleaning elements in the form of bristle clusters 4 in the area of the head 1. The top side of the handle 3 may include a thumb rest 5 designed as an indentation in the surface structure. The thumb rest 5 has a supporting shoulder 6 in particular in the longitudinal direction of the toothbrush toward the head and a supporting shoulder 7 in the longitudinal direction of the toothbrush toward the free end 8 of the handle. The thumb rest may be designed with an elliptical shape, as shown in particular by the top view of the toothbrush in FIG. 2, and may be provided with concentric elliptical fluting, which additionally increase the grip in the area of the thumb rest.

In another embodiment of the invention, the handle has one thumb rest each on the top side and on the bottom side adjacent to the neck. In the present case, the thumb rest on the bottom side is formed by the depression in the recess in the handle. The thumb rest has an elevated supporting structure in its edge areas, in particular in the longitudinal direction of the toothbrush, so that the user's thumb rests securely on both sides of the toothbrush between these elevated flanks or supporting structures or shoulders and does not slip off or slip into the recess during use.

The top side of the handle 3 may include additional indentations 9, 10, 11 and 12, which extend only a few millimeters into the structure of the surface of the handle and are connected to the thumb rest toward the free end 13 and are designed like the thumb rest to be as wide as a finger's width in the longitudinal direction. The indentations 9, 10, 11 and 12 may also be essentially elliptical in design, so that inclined supporting shoulders for the fingers are formed around the recesses. In deviation from the elliptical design of the indentations presented here, they may also have a different geometric shape.

The top view of the toothbrush according to FIG. 2 also shows a taper 14 of the handle 3. The taper 14 is thus provided in a plane approximately parallel to the bristle embedding plane 17 of the head 1. In this plane an enlarged outline cross section 15 is provided around the thumb rest 5 and at the other end of the handle next to the free end 13 there is an enlarged cross section of the handle 16.

As shown in FIG. 3, which shows a side view of the toothbrush, the taper is also slightly pronounced in the side view of the toothbrush approximately in the central area. The toothbrush may have an approximately s-shaped basic shape from its free end 13 on the handle end up to the free end 20 on the head end. The top side 18 of the toothbrush may include several supporting shoulders and/or high points which delineate the individual ellipses and/or the finger indentations 5, 9, 10, 11, 12 therein from one another.

The bottom side 19 of the toothbrush may include a concave and/or bow-shaped curvature in the handle area toward the center of the handle. Thus, in a side view of the toothbrush, a deeper section 21 is formed opposite the thumb rest 5 on the end of the handle next to the neck 2 and at the other end of the handle next to the free end 13, another deeper section 22 is formed. This greater curvature of the bottom side of the handle toward the inside is reproduced less markedly by the top side of the handle toward the outside as seen in a side view.

The bottom side of the handle not only has a concave curvature toward the interior of the toothbrush but it may also be designed to have a slightly wavy structure, as seen in a side view. This wavy shape 23 is also determined by the various handle depressions on the bottom side 19 of the handle 3 because the handle depressions on the bottom side are delineated from one another by flanks and/or shoulders and ultimately by high points. Here again, plastic material is thus saved in the handle area because the basic shape of the bottom side of the handle is designed so that the only handle walls provided there are those considered necessary for ergonomic reasons.

A first handle depression is also formed on the bottom side 19 next to the neck on the same end but opposite the thumb rest 5 on the top side. The thumb or index finger may thus be held in the handle depression 24 on the bottom side 19 next to the neck. The handle depression 24 has two elevated flanks 29, 30 arranged opposite one another in the longitudinal direction of the toothbrush, in particular along the longitudinal axis A-A in FIG. 2. The one flank 29 of the handle depression 24 is thus arranged next to the neck and prevents the finger accommodated in the handle depression from slipping off toward the neck, and the other shoulder or flank 30 of the handle depression 24 is arranged facing the free end 13. Similarly, additional handle depressions 25, 26, 27 and 28 may be formed on the bottom side 19 of the handle 3. On the whole, this handle thus provides up to five finger indentations on the top side of the handle and up to five corresponding handle depressions on the bottom side of the handle. Alternatively, fewer indentations or handle depressions may be formed. An especially good grip of the toothbrush and good handling are provided due to the plurality of handle depressions and the resulting wavy-shaped outline structure along the bottom side of the handle. FIG. 4 shows a longitudinal sectional diagram through the toothbrush along line A-A in FIG. 2. In the non-hatched area on the bottom side 19 of the handle 3, there are recesses 31, 32, 33, 34 and 35, which in this embodiment are not separated from one another by partitions and thus form a large common recess. These recesses 31 to 35 are bordered in the transverse direction by three walls, namely side walls 36 and 37 (see FIG. 5) and the inner rear side 38 of the top side of the handle area 3. These three walls form an inverted U in the cross-sectional plane that runs perpendicular to and across the sectional line A-A in FIG. 2. The recesses thus extend over the entire handle area of the toothbrush. Only one transitional area of the handle toward the free end 13 and a transitional area of the handle toward the neck are not provided with this recess. The inlet area of the recess 31 is bordered by a wall section 39 of this recess 31, which forms a border toward the outside. These wall sections 39 of the recess 31 which form a border toward the outside form the supporting surface for a handle depression 24 the width of a finger. The recess along with this thumb rest area may be designed to be essentially elliptical. The recesses and the other handle depressions on the bottom side of the handle may be designed similarly.

Due to the recess on the bottom side of the toothbrush, which is surrounded by walls on three sides as seen in cross section, good unmoldability of the toothbrush from the injection mold is ensured with no change. Furthermore, the U-shaped structure forms a mechanically rigid structure in the cross section of the wall sections around the recess, so the overall strength of the toothbrush is adequate. For example, in the case of recesses which form a passage through the toothbrush head on both sides, the flexural rigidity is much worse if material is to be saved in the handle area to the same extent as in the present case.

As shown in FIG. 5 and FIG. 6, the depressions 24 to 28 on the bottom side of the handle not only form a wavy shape with flank high points and concave indentations in the respective depressions in the handle around the recess, but may also form a wavy shape as seen in a view from above onto the recesses 31 to 35 due to the respective elliptical shape of the cavity of the recesses. An elliptical recess in the area of the thumb rest may be aligned with the next recess up to the end of the handle, so that the wall sections bordering the recess toward the outside, i.e., the transitional area between the inside of the recess and the outside, forms the finger rest areas and thus the depressions in the handle. There is thus a delineation of the depressions in the handle in two dimensions, namely in both the longitudinal direction and the transverse direction of the toothbrush, which is illustrated by the wavy shapes along the depressions in the bottom side of the handle according to the side view in FIG. 3 and the wavy shape in the view from above onto the bottom side of the toothbrush according to FIG. 5. The resulting deflection out of the bottom side of the handle due to the shape of the recesses is transferred from the bottom side of the handle, so that the bordering wall sections toward the outside form depressions of finger width in the handle.

Finger width in this case means approximately at least 1 cm wide in the longitudinal direction of the depression the handle of the toothbrush. The length of the depression in the handle from one flank high point to the next flank high point of the adjacent depression in the handle in the longitudinal direction of the handle varies between 10 millimeters and 40 millimeters for the different depressions in the handle. Each depression in the bottom side of the handle may be designed to be of a different size because this requires different amounts of space for the different fingers and the taper of the toothbrush handle influences the width and length of the depressions in the handle anyway.

The wall thickness of the top side of the handle which corresponds to the side of the tooth-cleaning elements may be designed to be thinner in this variant than the wall thickness of the side walls 36 and 37 of the handle, resulting in a certain flexibility of the handle and the brush body in the plane through the section A-A in FIG. 2 and permitting a reduced flexibility of the toothbrush in the lateral direction. Furthermore, the thinner design of the top side of the handle allows the implementation of other decorative structures, which appear with a lighter density than the other walls of the toothbrush when using a transparent or translucent plastic as the primary material for the toothbrush body.

In another embodiment, the side walls of the handle form a taper. The taper in combination with the handle depressions thus forms another improvement in the ergonomic design of the toothbrush and in the variability of the possibilities for use of the toothbrush for Asian users in particular. In addition, the taper ensures further savings of material even in the outside area of the handle because a widening of the cross section is provided only in the end areas of the handle, i.e., at the locations where the enlarged outside cross section of the handle contributes toward an ergonomic improvement.

As shown in FIG. 5 and FIG. 6, the toothbrush may also have a tongue cleaner 40 formed by ribs on the bottom side of the head. However, the handle structure shown here can be combined with any bristle pattern or tongue-cleaning pattern or even without a tongue-cleaning pattern on the back side of the head. Furthermore, as an alternative, fewer depressions may be formed in the bottom side of the handle. In another variant, openings are also provided on the top side of the handle if the associated destabilization of the handle structure is desired.

The toothbrush may be made of polypropylene or any other plastic material. The toothbrush may be produced by an injection molding process. Certain plastic components, in particular elastomer plastics may be formed on the head, the neck or handle area in single or multi-component injection molding processes.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”

Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. 

1. A toothbrush having a top side; an opposite bottom side; a head on which tooth cleaning elements are provided; a handle having walls and a recess; and a neck which connects the head to the handle, wherein the recess is located on the side of the handle opposite the side having the tooth-cleaning elements, the recess being open only toward the bottom side so that the handle walls bordering the recess form an inverted u-shaped cross-section.
 2. The toothbrush of claim 1, wherein the walls of the handle form a taper.
 3. The toothbrush of claim 1, wherein the handle has a thumb rest on both the top side and the bottom side, each adjacent to the neck.
 4. The toothbrush of claim 1 wherein the top side of the handle has at least one indentation that is a finger's width in size.
 5. The toothbrush of claim 1, wherein the bottom side of the handle forms a conical curvature.
 6. The toothbrush of claim 1, wherein the sides of the inverted u-shaped handle walls are thinner than the top. 